Dietary niche partitioning of two sympatric mesocarnivores in a cool temperate forest ecosystem: The influence of seasonal variation and apex carnivores

Characterizing the dietary niche partitioning of sympatric mesocarnivores is fundamental for understanding their mechanisms of coexistence and ecosystem function. By utilizing scat DNA and DNA metabarcoding, our study revealed a detailed picture of the trophic interaction between two mesocarnivores in a cool temperate forest ecosystem in Northeast China. Both red foxes (Vulpes vulpes) and leopard cats (Prionailurus bengalensis) consumed a diverse range of prey (52 prey taxa from 11 orders) dominated by Rodentia (56.5–64.9%). Bipartite trophic network analysis suggested that both predators are generalists and have a high degree of niche overlap (Pianka's index = 0.77). However, diet patterns differed between the predators. Both predators consumed more diverse prey during the snow-free period than during the snow-covered period, which resulted in lower niche overlap between the predators (Pianka's index = 0.43). Another important source of diet niche partitioning was the proportion of large prey consumed, with red foxes consuming more ungulates than leopard cats do throughout the year in regions with two apex carnivores, tigers (Panthera tigris) and leopards (P. pardus). The presence of apex carnivores provides more stable carrion resources, which facilitates dietary niche partitioning and the coexistence of mesocarnivores. Our study provides important clues about the strategies of dietary niche partitioning between sympatric mesocarnivores, which is critical for understanding coexistence within carnivore communities.